Oh my god, it is available! There is a plugin for eclipse that makes it fullscreen compatible for Mac OSX Lion (10.7). Find out the details here

http://danielgerber.wordpress.com/2011/07/25/using-eclipse-in-fullscreen-mode-under-mac-os-x-10-7-lion/

In short you only need to add the following update location (http://github.bandlem.com/) via Help->Install new software…

via http://alblue.bandlem.com/2011/07/full-screen-support-for-eclipse-on-osx.html